Chronic wounds present an enormous burden to patients and the health care system worldwide. Traditional clinical diagnosis of bacterial infections in chronic wounds rely on subjective clinical signs and symptoms assessment based on white light visualization of the wound and microbiological sampling (swabbing/biopsy), which can be inaccurately obtained and take days. This can also result in delayed diagnosis and suboptimal treatment decisions for patients.

A pilot study of 58 patients with chronic wounds evaluated a novel handheld fluorescence imaging device to detect pathogenic bacteria (including Staphilococci and Pseudomonas species) based on intrinsic autofluorescence (AF) signals of the bacteria and wound tissues at the point-of-care. Imaging was performed with blinded validation by microbiological cultures swabs.

Initial clinical results demonstrated that AF accurately detected clinically-significant bioburden in the wound bed; 74.5% compared with 52.5% accuracy with conventional diagnostic assessment (p=0.003). Additionally, AF accurately detected clinically-significant bioburden in surrounding locations close to wounds 67.1% of the time, where traditional methods did not examine or sample. The bacterial load and biodistribution can be mapped in real-time and safely within the wound bed, periphery and at other remote areas that would not have been identified by traditional diagnostic approaches (but may serve as a source of re-contamination/infection).

Fluorescence imaging in a handheld device format provides a safe and more accurate (or targeted) wound sampling method for laboratory culture testing. Also, rapid visualization and quantification of bacterial load in the wound bed, periphery and remote areas offers a new means for clinicians to make real-time treatment decisions for administration of antimicrobial and/or debridement treatments at the bedside while using the images for documentation and monitoring treatment response in individual patients.